Anaerobic respiration: Respiration not requiring oxygen. Anaerobic bacteria do not need oxygen to grow; in fact, oxygen is usually toxic to them. An anaerobic environment lacks oxygen.

Alveoli: A tiny, thin-walled, capillary-rich sac in the lungs where the exchange of oxygen and carbon dioxide takes place

Bronchi: Either of two main branches of the trachea, leading directly to the lungs.

Bronchiole: Any of the fine, thin-walled, tubular extensions of a bronchus

Cilia: microscopic hair like process extending from the surface of a cell or unicellular organism.

CPR:An emergency procedure, often employed after cardiac arrest, in which cardiac massage, artificial respiration, and drugs are used to maintain the circulation of oxygenated blood to the brain.

Diaphragm: A muscular membranous partition separating the abdominal and thoracic cavities and functioning in respiration.

Epiglottis:The thin elastic cartilaginous structure located at the root of the tongue that folds over the glottis to prevent food and liquid from entering the trachea during the act of swallowing.

Exhalation: breathing out.

Gas exchange: occurs between the blood and the alveolar air across the respiratory membrane

Inhalation: breathing in

Larynx: The part of the respiratory tract between the pharynx and the trachea, having walls of cartilage and muscle and containing the vocal cords enveloped in folds of mucous membrane.

Lung: Either of two spongy, saclike respiratory organs in most vertebrates, occupying the chest cavity together with the heart or functioning to remove carbon dioxide from the blood and provide it with oxygen.

Oxygen debt: lack of oxygen

Pharynx:The section of the alimentary canal that extends from the mouth and nasal cavities to the larynx, where it becomes continuous with the esophagus.

Respiration:breathing

Respiratory control center:

Trachea:the windpipe

Vital capacity:The amount of air that can be forcibly expelled from the lungs after breathing in as deeply as possible.